The present invention relates to an onboard vehicle environment recognition system for recognizing a driving environment of a vehicle by detecting another vehicle ahead and road geometry.
Japanese Patent Provisional (KOKAI) Publications Nos. 6(1994)-36033 and 7(1995)-244717 show conventional vehicle environment recognition systems. A conventional recognition system as disclosed in these documents is designed to perform an integrating operation in the coordinate system of input images. When the vehicle moves laterally along the right and left direction, input images move laterally in accord with the lateral movement of the vehicle. Therefore, the integration of images of a preceding vehicle and a white line painted on a road involves an undesired lateral deviation. This causes errors in the detection of a vehicle position, and a white line position. When the vehicle moves from one lane to another lane, the conventional recognition system may erroneously detect, as a preceding vehicle, another vehicle which is no longer in the same lane.